How I draw from imagination

This is 2 pages of a diary entry in last month. All of these panels were drawn from my imagination, but shortly after each event took place. 

How do I draw from imagination? I picture the image in my mind. Try to hold it there. And I contour the shapes on paper with my pen. Sure, the image may not be as vivid as a a scene in real life, but since I'm drawing it loose, I only need a rough image. When I draw this way, I often keep it more simple. The main goal is to tell a story. To tell a story, I don't need elaborate shading and details. I just need people to know what is going on in the scene. So I make sure the main character stands out clearly. And it is clear enough what is happening or what the character is doing. I must say that doing lots of quick urban sketching does help build my confidence in doing these scenes. It does build my visual vocabulary and it helps me to better know how to crop a scene too. So, want to improve on drawing from imagination? Do more urban sketching!:)

I didn't want to spend a lot of time colouring these pages so I've kept it really really minimal. Mainly, I add in a mid-tone flat colour (just one in this one) strategically. The main aim is to give the area where the main character(s) is the highest contrast. That's it. If you were to study each panel, and look for the area where there is lots of contrast, the main character(s) will be there. I added the flat colours using photoshop in another layer and set the layer to multiply. And I'm able to do it within 5-10mins. I think it's effective in helping the page do its job- tell a story clearly:)